Tower and mobile crane safety

HAZARD
Cherie Berry, Commissioner of Labor
1- 800- 625- 2267 www. nclabor. com
Two recent tower crane accidents— one in New York and
one in Florida— resulted in multiple fatalities. These events
highlighted the inherently dangerous nature of work involving
not only tower cranes but all types of cranes.
Cranes must be inspected and used properly. Many fatalities
can occur when the crane boom, load line or load contacts
power lines and shorts electricity to ground. Other incidents
happen when workers are struck by the load, are caught inside
the swing radius, or fail to assemble/ disassemble the crane
properly. Additionally, improper crane setup accounts for
approximately 50 percent of crane accidents.
Cranes must be erected, dismantled and operated by competent
people who have the necessary training and experience.
Employers should have written procedures for each type of crane
and their procedures should be based on the manufacturer’s
instructions. The procedures should be available on site, and
those involved in the work should be familiar with them.
Comply with the manufacturer’s specifications and
limitations applicable to the operation of any crane.
Cranes are to be operated only by qualified and trained
personnel.
A designated competent person must inspect all crane
machinery and equipment before and during use to
ensure its safe operation.
Be sure the crane is on a firm/ stable surface and level.
During assembly/ disassembly of the crane’s boom, do not
unlock or remove pins unless sections are blocked and
secure ( stable).
Properly plan lifting operations and always supervise
them appropriately.
Watch for overhead electric power lines and maintain at
least a 10- foot safe working clearance from the lines.
Inspect all rigging prior to use; do not wrap hoist lines
around the load.
Be sure to use the correct load chart for the crane’s current
configuration and setup, the load weight and lift path.
Do not exceed the load chart capacity while making lifts.
Do not make any modifications or additions that affect
the capacity or safe operation of the equipment without
the manufacturer’s written approval.
Fully extend outriggers and barricade accessible areas
inside the crane’s swing radius.
Division of Occupational Safety and Health
1101 Mail Service Center, Raleigh, NC 27699- 1101
Tower and Mobile Crane Safety
Tower crane collapse into adjacent building.
Result of outriggers improperly set.
Raise the load a few inches, hold, verify capacity/ balance,
and test brake system before delivering it.
Do not move loads over workers.
Be sure to follow signals and manufacturer’s instructions
while operating cranes.
Overloading occurs when the
rated capacity of a crane is
exceeded while a load is being
lifted and maneuvered, resulting
in upset or structural failure.
Overloading occurs when poorly
trained personnel are allowed to
operate cranes. The operator must
always know the weight of the
load. Some variables that affect
the lifting capacity of a crane:
The ability to lower a boom increases the radius and
reduces capacity.
The ability to extend a hydraulic boom increases the
radius and reduces lifting capacity.
The ability to lower a boom while extending a boom
quickly reduces lifting capacity.
The crane’s tipping capacity can vary when the boom is
positioned at the various points of the compass or clock
in relation to its particular carrier frame.
The operator may neglect to extend the outriggers or the
crane is positioned on soft ground.
The operator may mistakenly rely upon perception,
instinct or experience to determine whether the load is
too heavy and may not respond fast enough when the
crane begins to feel light.
Another serious condition, two- blocking, occurs when the
hoist block or hook assembly comes into contact with the
boom tip, causing the hoist line to break and the hook and load
to fall, endangering workers below.
Tower Crane Inspection Checklist
Preliminary Cab
Foundation bolts/ anchors Fire extinguisher
Main power disconnect switch Load chart
Hook sheaves/ swivel Window glass
Power contact grounding Operations manual
Support guys/ anchors
Tower Crane Operation
Ladders/ platforms Control function
Section connecting bolts/ pins Swing brake
Safety rails/ chains Moment overloads
Tie- in assembly( s) Hoist overloads
Cord and lacing welds Trolley cable/ brake
Power cable Sheaves
Hydraulic hoses for leaks Gear limits
Gear boxes for oil level/ leaks Trolley limits
Slewing ring bolts Luffing limits
Counterweights secure Hoist limits
Motor/ winch hold- down bolts Proximity to power lines
Wire rope condition
Hoist drum spooling
Mobile Crane Inspection Checklist
Manufacturer’s operating and maintenance manual
Guarding exposed moving parts
Swing clearance protection
Boom stops
Jib boom stops
Boom angle indicator
Boom hoist disconnect, automatic boom hoist shutoff
Two- blocking device
Powered controlled lowering
Leveling indicating device
Sheaves
Main hoist and auxiliary drums system
Main boom, jib boom, boom extension
Load hooks and hook blocks
Hydraulic hoses, fittings, and tubing
Outriggers
Load rating chart
Wire rope
Cab— controls, gauges, glass, fire extinguisher, warning
lights, horn, wipers, etc.
Braking systems
Turntable/ crane body
Counterweight
Rubber tires ( where applicable)
Stay in touch with today’s workplace issues.
Sign up to receive a free subscription to the NC Labor Ledger at
www. nclabor. com/ news/ ledgersubs. htm
Printed 5/ 08
2,500 copies of this public document were printed at a cost of $ 114.60, or $. 04 per copy.
Result of overloaded crane.

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HAZARD
Cherie Berry, Commissioner of Labor
1- 800- 625- 2267 www. nclabor. com
Two recent tower crane accidents— one in New York and
one in Florida— resulted in multiple fatalities. These events
highlighted the inherently dangerous nature of work involving
not only tower cranes but all types of cranes.
Cranes must be inspected and used properly. Many fatalities
can occur when the crane boom, load line or load contacts
power lines and shorts electricity to ground. Other incidents
happen when workers are struck by the load, are caught inside
the swing radius, or fail to assemble/ disassemble the crane
properly. Additionally, improper crane setup accounts for
approximately 50 percent of crane accidents.
Cranes must be erected, dismantled and operated by competent
people who have the necessary training and experience.
Employers should have written procedures for each type of crane
and their procedures should be based on the manufacturer’s
instructions. The procedures should be available on site, and
those involved in the work should be familiar with them.
Comply with the manufacturer’s specifications and
limitations applicable to the operation of any crane.
Cranes are to be operated only by qualified and trained
personnel.
A designated competent person must inspect all crane
machinery and equipment before and during use to
ensure its safe operation.
Be sure the crane is on a firm/ stable surface and level.
During assembly/ disassembly of the crane’s boom, do not
unlock or remove pins unless sections are blocked and
secure ( stable).
Properly plan lifting operations and always supervise
them appropriately.
Watch for overhead electric power lines and maintain at
least a 10- foot safe working clearance from the lines.
Inspect all rigging prior to use; do not wrap hoist lines
around the load.
Be sure to use the correct load chart for the crane’s current
configuration and setup, the load weight and lift path.
Do not exceed the load chart capacity while making lifts.
Do not make any modifications or additions that affect
the capacity or safe operation of the equipment without
the manufacturer’s written approval.
Fully extend outriggers and barricade accessible areas
inside the crane’s swing radius.
Division of Occupational Safety and Health
1101 Mail Service Center, Raleigh, NC 27699- 1101
Tower and Mobile Crane Safety
Tower crane collapse into adjacent building.
Result of outriggers improperly set.
Raise the load a few inches, hold, verify capacity/ balance,
and test brake system before delivering it.
Do not move loads over workers.
Be sure to follow signals and manufacturer’s instructions
while operating cranes.
Overloading occurs when the
rated capacity of a crane is
exceeded while a load is being
lifted and maneuvered, resulting
in upset or structural failure.
Overloading occurs when poorly
trained personnel are allowed to
operate cranes. The operator must
always know the weight of the
load. Some variables that affect
the lifting capacity of a crane:
The ability to lower a boom increases the radius and
reduces capacity.
The ability to extend a hydraulic boom increases the
radius and reduces lifting capacity.
The ability to lower a boom while extending a boom
quickly reduces lifting capacity.
The crane’s tipping capacity can vary when the boom is
positioned at the various points of the compass or clock
in relation to its particular carrier frame.
The operator may neglect to extend the outriggers or the
crane is positioned on soft ground.
The operator may mistakenly rely upon perception,
instinct or experience to determine whether the load is
too heavy and may not respond fast enough when the
crane begins to feel light.
Another serious condition, two- blocking, occurs when the
hoist block or hook assembly comes into contact with the
boom tip, causing the hoist line to break and the hook and load
to fall, endangering workers below.
Tower Crane Inspection Checklist
Preliminary Cab
Foundation bolts/ anchors Fire extinguisher
Main power disconnect switch Load chart
Hook sheaves/ swivel Window glass
Power contact grounding Operations manual
Support guys/ anchors
Tower Crane Operation
Ladders/ platforms Control function
Section connecting bolts/ pins Swing brake
Safety rails/ chains Moment overloads
Tie- in assembly( s) Hoist overloads
Cord and lacing welds Trolley cable/ brake
Power cable Sheaves
Hydraulic hoses for leaks Gear limits
Gear boxes for oil level/ leaks Trolley limits
Slewing ring bolts Luffing limits
Counterweights secure Hoist limits
Motor/ winch hold- down bolts Proximity to power lines
Wire rope condition
Hoist drum spooling
Mobile Crane Inspection Checklist
Manufacturer’s operating and maintenance manual
Guarding exposed moving parts
Swing clearance protection
Boom stops
Jib boom stops
Boom angle indicator
Boom hoist disconnect, automatic boom hoist shutoff
Two- blocking device
Powered controlled lowering
Leveling indicating device
Sheaves
Main hoist and auxiliary drums system
Main boom, jib boom, boom extension
Load hooks and hook blocks
Hydraulic hoses, fittings, and tubing
Outriggers
Load rating chart
Wire rope
Cab— controls, gauges, glass, fire extinguisher, warning
lights, horn, wipers, etc.
Braking systems
Turntable/ crane body
Counterweight
Rubber tires ( where applicable)
Stay in touch with today’s workplace issues.
Sign up to receive a free subscription to the NC Labor Ledger at
www. nclabor. com/ news/ ledgersubs. htm
Printed 5/ 08
2,500 copies of this public document were printed at a cost of $ 114.60, or $. 04 per copy.
Result of overloaded crane.